Patent GB-100183-A (GB)
Title: Improvements in Blow-off Valves.
Inventor: KAHN SAMUEL
IPC: B60C23/00
Filed: 1916-03-13
Abstract: 100,183. Kahn, S. March 13, 1915, [Convention date]. Safety - valves; tyre and like inflating valves. - A valve device, particularly for use as a tyre - inflating valve, is fitted with a relief valve adapted to control a series of holes between a pair of ring-seatings in addition to the usual check valve arranged to control a central aperture in the seat, to prevent the tyre or container from being charged above a predetermined pressure, the relief valve being arranged so that it can be used to test whether the pressure has fallen below a predetermined minimum. In the form shown in Fig. 1, the valve casing is formed in two parts 11, 21 screwed together, the part 11 being provided with a flange 13, recess 12, and nut 14 for securing the valve to the tyre 10. The part 21 is internally tapered to engage the part 11 and to accommodate the seat 63 for the check valve 58 and the seat 43 for the relief valve 46. The seat 43 is provided with a tubular extension 49 extending to the upper part of the casing, where it is secured by a nut 55 bearing against a packing-washer 66. The spindle 60 of the check valve, which has a removable valve face 61, passes through this extension and is provided at its upper end with a perforated flange 58<1> adapted to serve as an abutment for a spring 56. The relief valve has a tubular guide 48 adapted to slide on the extension 49, and has a valve face adapted to bear against annular ridges 45 surrounding a circle of perforations 44 in the valve seat. The relief valve is loaded by a spring 50 bearing against a sliding abutment 51, normally bearing against a stop 53 secured to the member 49 to give the minimum blow-off pressure, but provided with a pin 42 passing through a bayonet-slot 41 in the casing and engaging a sliding sleeve 40, whereby the spring may be further compressed to give the maximum blow-off pressure. The valve is rendered absolutely air-tight by means of a cap 36, screwed on to the casing and provided with a washer 37 held in an undercut groove by a screw having a recessed head, adapted, when the cap is removed and inverted, to depress the check-valve spindle while preventing the escape of air. A second cap 30 is secured to the washer holding the valve casing to the wheel rim. This cap has partflanges 27 adapted to be passed through gaps in the flange 32 and then turned to press against cam-surfaces on the sides of the groove. In Fig. 5, the device is shown adapted to be readily attached to the nipple of an ordinary tyre valve. The coupling-device comprises a block 68 fitted with sliding threaded members 73 adapted to engage the nipple when forced.inward by a sliding sleeve engaging wedge surfaces on the blocks. The motion of the blocks is limited by pins 74 engaging grooves 75. The block 68 is also provided with a washer 67 and a tubular member 38<1> adapted to unseat the check valve. In this modification, the pin 42 extends through a straight slot in the casing into a sliding member 40<a> adjusted bv a member 40b having pins 76 engaging a helical groove on the casing. The member 40b has a projection adapted to take into recesses in the member 40<a> to prevent accidental movement and to indicate the amount of compression of the loading- spring. In a further modification, adapted for use on the end of a hose supplying compressed air, the check valve isl inverted to act as a valve closing with flow, and is adapted to be unseated during the act of coupling by the valve spindle contacting with the check-valve spindle in the valve. The Specification as open to inspection under Sect. 91 (3) (a) comprises also another form in which the check valve and relief valve are arranged side by side, and a third valve is provided interconnected with the blow-off valve to shut off the supply while the relief valve is discharging. This subject-matter does not appear in the Specification as accepted.